Quick-change axial pin-tumbler lock assembly



QUICK-CHANGE AXIAL PIN-TUMBLER LOCK ASSEMBLY Filed Jan. 9, 1964 W. J. KERR May 17, 1966 3 Sheets-Sheet 1 INVENTOR' WILLIAM J. KERR May 17, 1966 w. J. KERR 3,251,205

QUICK-CHANGE AXIAL PIN-TUMBLER LOCK ASSEMBLY Filed Jan. 9, 1964 3 Sheets-Sheet z INVENTOR: WILLIAM J. KERR I May 17, 1966 w. J, K R 3,251,205

QUICK-CHANGE AXIAL PIN-TUMBLER LOCK ASSEMBLY Filed Jan. 9, 1964 3 Sheets-Sheet 5 \I III INVENTOR. WILLIAM J. KERR United States Patent 3,251,205 QUICK-CHANGE AXIAL PlN-TUMBLER LOCK ASSEMBLY William J. Kerr, Gienview, lll., assignor to Chicago Lock Company, (Ihicago, EL, a corporation of Illinois Filed Jan. 9, 1964, Ser. No. 336,795 20 Claims. Cl. 70-363) The present invention relates to lock assemblies and has particular reference to a lock assembly of the axial pin-tumbler type wherein the split tumblers that are associated therewith are circumferentially spaced about, and extend parallel to, the central longitudinal axis of the lock barrel, are spring-pressed forwardly, and cooperate with a key having forwardly facing circumferentially spaced tumbler-engaging shoulders.

Locks of the aforementioned type find wide application in connection with the cabinet doors of vending machines which are installed in public places. Managerial policy dictates that the tumbler pin combinations of such vending machine lock assemblies shall be changed frequently. Complete lock assembly substitution is undesirable inasmuch as it requires the service personnel to transport a heavy load of lock assemblies. Therefore, it is the current practice for the service personnel to effect a change in the tumbler pin combination in the field.

In order to change the tumbler pin combination in the field, it has heretofore been necessary to work from the rear or inner side of the cabinet door, dismantling as much of the lock assembly as is necessary to render the split tumbler pins accessible for removal and subsequent substitution or replacement. Apart from the inconvenience of working from the back side of the cabinet door, space limitations frequently are such that a wide open cabinet door is a hindrance to passers-by as, for example, on a narrow subway platform. Still further, the design of present-day lock assemblies is such that in effecting a change-over operation, the operator is burdened with the inconvenience of keeping track of numerous lock parts, this being true even when he is supplied with an assembly jig to facilitate his work.

The present invention is designed to overcome the above-noted limitations that are attendant upon the construction of present-day vending machine lock assemblies and upon change-over operations in connection therewith. Toward this end, the invention contemplates the provision of a novel lock assembly of the axial pin-tumbler type, the assembly being so designed that a tumbler pin combination change may readily be made with the operator performing the necessary work from the front or outside of the cabinet door and with the door in its closed or nearly closed position. This being the principal object of the invention, it is a further object to provide such a lock assembly which does not require that the operator carry an assembly jig for change-over operations, or that he transport any lock parts whatsoever other than the replacement key to fit the new tumbler pin combination after the change-over has been effected.

A still further object of the invention is to provide a lock assembly which is readily susceptive to a changeover operation without necessitating the laying down of lock parts, either on a bench or other temporary support, the operator being capable of performing all of the necessary manipulations while in full possession of the parts undergoing manipulation or treatment.

With these and other objects in view, which will become more readily apparent as the nature of the invention is better understood, the invention consists of the novel construction, combination and arrangement of parts shown in the accompanying three sheets of drawings forming a part of this specification.

3,25l,25 Patented May 17, 1966 ice I In these drawings:

FIG. 1 is a front perspective view of a lock assembly constructed in accordance with the principles of the present invention, the operating key of the assembly being shown in its assembly unlocking position within the lock cylinder;

FIG. 2 is a rear perspective view of the lock assembly;

FIG. 3 is an exploded front perspective view of the lock assembly;

FIG. 4 is a sectional view taken substantially on the vertical plane indicated by the line 44 of FIG. 1 and in the direction indicated by the arrows;

FIG. 5 is a transverse sectional view taken on the line 5-5 of FIG. 4;

FIG. 6 is a transverse sectional view taken on the line 6-6 of FIG. 4;

FIG. 7 is an exploded perspective view, schematic in its representation, of the lock assembly and illustrating the manner in which tumbler pin change-over operations are effected in situ;

FIG. 8 is a front elevational view of the lock assembly with the cap removed, the view being taken on the vertical plane that is indicated by the line 88 of FIG. 3 and in the direction of the arrows;

FIG. 8a is an enlarged sectional view taken on the line 8a--8a of FIG. 8;

FIG. 8b is a sectional view taken on the line 8b-8b of FIG. 5;

FIG. 9 is a transverse sectional View similar to FIG. 6 but showing the parts in the positions which they assume when the lock assembly is in its locked condition; and

FIG. 10 is a sectional view similar to FIGS. 6 and 9 but showing the parts in the positions which they assume during tumbler pin change-over operations.

Referring now to the drawings in detail and in particular to FIGS. 1 to 4, inclusive, a preferred form of lock assembly constructed according to the present invention has been designated in its entirety by the reference numeral it) and a key for operating the lock assembly is identified by the reference numeral 12. The lock assembly is of the axial pin-tumbler type, which is to say that the split tumbler pins that are associated therewith and form parts thereof extend in the axial direction of the lock barrel.

The lock assembly It involves in its general organization a fixed tubular lock barrel 14 having a forwardly extending axial rim flange 16 (see FIG. 4) and a rearwardly extending shank portion 18 of the interrupted thread type. By interrupted thread type is meant that the external threads 26 of the shank portion are interrupted by op positely disposed flats Z2 and 24 (see FIGS. 2 and 3). The lock assembly 10 is shown in FIGS. 1 and 4 as being operatively installed upon a swinging door panel 26 by means of a nut 28 which is threadedly received on the threads 20 of the shank portion and cooperates with a protective washer 30 in clamping the door therebetween, the barrel 14 projecting rearwardly through an opening 32 in the door panel 26.

The lock barrel 14 is provided with a central axial open ended bore 40 within which there is rotatably disposed a lock shaft 42. .T he rear end of such shaft projects outwardly of the barrel l4 and is threaded as at 44. Flats 46 on the threaded rear end of the shaft 42 (see FIGS. 2 and 3) cooperate with a substantially rectangular hole 48 in a radial locking cam 50 in maintaining the cam non-rotative on the shaft. A nut 52 on the threaded rear end of the lock shaft 42 serves to clamp the locking cam 50 against the rear end of the barrel 14. The locking cam 50 is designed for cooperation with a locking shoulder 54 (see FIG. 4) in maintaining the door panel 26 in its closed position against the usual jamb for the door panel.

is provided for a purpose that will be made clear presently.

Each socket 60 slidably receives therein the usual nonrotative barrel pin 64 of a split tumbler pin arrangement, the cooperating rotative shaft pin 66 of the arrangement being slidably disposed in an axially extending bore 68 in an enlarged head 70 on the front end of the lock shaft 42 and nested within the shallow forwardly facing recess that is afforded by the rim flange 16 of the lock barrel 14. The non-rotative pins 64 are yieldingly urged in a forward direction by means of spiral compression springs 72 within the sockets 60. The rotative pins 66 cooperate with respective shoulders 74 (see FIG. 3) on the tubular part of the key 12 in the usual manner of axial pin-tumbler type lock assemblies so that when the split tumbler pins are depressed so that the splits or juncture regions between the pins 64 and 66 are disposed in the same transverse plane, the lock shaft 42 may be turned within the barrel 14, otherwise not. A forwardly extending key-centering post 71 on the front end of the lock shaft 42 and forwardly of the enlarged head 70 cooperates with the usual socket 73 in the tubular part of the key in aligning the key 12 and the shaft 42. A notch '75 in the post 71 cooperates with a longitudinally extending spline 77 on the key so that torque may be applied to the shaft 42 by the key 12 when the split tumbler pin arrangement of the lock assembly permits, as is conventional in connection with axial tumbler-pin type lock assemblies.

The arrangement of parts thus far described is conventional and no claim is made herein to any novelty associated therewith, the novelty of the present invention residing rather in the novel construction, combination and arrangement of parts by means of which pin-tumbler changeover operations may be conducted to adapt the lock assembly to a different operating key.

In the normal operation of the lock assembly 10, the lock shaft 42 is capable of being rotated throughout an angle of 90 between the locked condition of the cam 50 as shown in full lines in FIGS. 1 and 2 and the unlocked condition of the cam as shown in dotted lines in FIGS. 2 and 3. The shaft 42 is also capable of being turned in a clockwise direction as viewed in FIGS. 2 and 5 an additionalsmall angle to the overrun position shown in broken or dot-dash lines when released by a combined latch and limit stop plunger 76 (see FIGS. 6, 9 and 10) to enable pin-tumbler change-over operations to be instituted, all in a manner that will be made clear presently.

In the illustrated locked condition of the lock assembly 10, the locking cam 50 extends vertically as shown in FIGS. 1, 2 and 4 and is disposed behind the locking 7 shoulder 54. In the unlocked condition of the assembly, the locking cam extends horizontally as shown in FIG. 3. The plane of the finger grip 7 8 that is associated with the key 12 at all times extends in the axial plane of the locking cam 50 and the key normally cannot be removed from the lock assembly except when the latter is in its locked condition. Since a vending machine cabinet is never left unattended in an unlocked condition, there is no necessity for making provision for key removal except when the cabinet is locked. In the case of a coin-operated public storage locker, when the locker is left unattended in its unlocked condition, the key is always securely in position within the lock assembly against removal.

To thus capture the key in the locked condition of the lock assembly 10, an annular cap 80 having the usual inturned key-receiving rim 81 is provided. The protective washer 30 is formed with a forwardly projecting wall 82 which establishes a shallow forwardly facing cylindrical recess 84 for telescopic reception therein of the inner end portion of the cap 80. The cap is provided with two rearwardly extending diametrically opposite hook portions 86 (see FIGS. 3 and 7) which encompass and slidingly hook behind an interrupted circular radial rim flange 38 on the front end of the enlarged head 70 of the lock shaft 42. The front faces of the inwardly extending parts of the hook portions 86 and the rearward face of the rim flange 88 constitute axially opposed shoulders on the cap and the shaft head, respectively (see FIG. 4) for normally preventing removal of the cap 80. The rim flange 88 normally prevents removal of the cap from the lock so that the hook portions 86 of the cap 80 register with two diametrically disposed voids or notches 120 in the rim flange 88 and permit forward movement and consequent removal of the cap from the forwardly projecting wall 82 of the protective washer 30. The cap 80 is formed with a central opening 92 (see FIG. 7) which is coaxial with the key post 71 and through which the tubular part of the key 12 is adapted to be projected for lock entry purposes. A notch 94 cooperates with a radial lug 96 on the tubular part of the key 12 to permit entry of the key in proper circumferential register with the pin-tumblers for immediate lock manipulations after initial key insertion. The lug 96 rides behind the rim of the opening 92 and prevents key removal except when the lug and notch are in register, i.e., when the lock assembly is in its locked condition.

Limit stop means are provided for determining the three limiting positions of which the lock shaft 42 is capable of assuming. This means includes the previously mentioned plunger 76 (see FIGS. 6, 9 and 10) which, in addition to its shaft-limiting function, also serves as a latch plunger for normally constraining the shaft 42 to rotate within its normal limits between locked and unlocked positions, but allowing the shaft to be rotated an additional small angle when it is desired to release the cap 80 for pintumbler change-over operations.

The plunger 76 is slidable in a transverse socket 100 (see FIGS. 4 and 6) in the shaft 42 and it is springpressed as at 102 so that it projects radially outwardly beyond the cylindrical confines of the shaft. In order to limit rotation of the shaft within its 90 range of angular turning movement between the locked and unlocked condition of the lock assembly, a relief area 104 of the bore 40 in the barrel 14 affords a pair of radial shoulders 106 and 103, respectively. The plunger 76 projects into the relief area 104 and when it is positioned against the shoulder 106 as shown in FIG. 6, the lock assembly 10 is in its locked condition with the locking cam 50 extending vertically. When the plunger '76 is positioned against the shoulder 108 as shown in FIG. 9, the lock assembly 10 is in its unlocked condition with the locking cam 50 extending horizontally.

When the plunger 76 is positioned against the shoulder 108 it is disposed in radial register with an access opening 110 (see FIGS. 6, 9 and 10) which is formed in the wall of the tubular lock barrel 14 and communicates with the relief area 104. This access Opening 110 is provided for the purpose of enabling the plunger 76 to be depressed by means of a suitable tool such as the tool 112 of FIGS. 3 and 9. Upon depression of the plunger 76, the latter is withdrawn from the shoulder 103 so that the shaft 42 may be further turned to bring the plunger into engagement with a third shoulder 114 as shown in FIG. 10 preparatory to effecting tumbler pin substitution or interchange operations for pin-tumbler change-over purposes. Stated otherwise, the plunger 76 is a combined latch and limit stop plunger. Normally, for panel-locking and panel-unlocking operations, the plunger 76 operates between the two shoulders 106 and 108 and confines the shaft 42 to a 90 angular turning movement, as between the positions of FIGS. 6 and 9. For pin-tumbler changeover operations, after the plunger has been depressed by the tool 112, a further approximately 25 overrunning movement of the shaft is made possible to bring the plunger 76 into engagement with the shoulder 114. The

. plunger 76 is accessible to the tool 112 only in the unlocked position of the lock assembly as shown in FIGS. 3 and 9. In this unlocked condition, the end of the plunger 76 is exposed to the tool 112 through a notch 115 (see FIGS. 1 and 3) in the end face 22 of the barrel 14.

Referring now to FIGS. 4, 5 and 8, it is to be noted that in all normal positions of the parts of the look assembly 10,.the cap 8% is not removable from the lock assembly due to the fact that the rearwardly extending diametrically opposite hook portions 86 thereof project behind the arcuate rim flange 83. Similarly, the key 12, in all positions thereof except its position of entry and withdrawal from the lock assembly, cannot be removed from the lock assembly by reason of the fact that the lug 96 thereof is disposed behind the inturned rim $1 of the cap 30. Since the key is not removable from the cap and, since the cap is not removable from the barrel 14, it follows that the key remains captured in the lock assembly 10 at all times except when the lug 96 on the key is in register with the notch 94 in the inturned rim 81 of the cap 89).

Still referring to FIGS. 4, 5 and 8, it will be observed that when the shaft 42 has been turned throughout the additional approximately so that the plunger 76 (FIG. 10) bears against the shoulder 114 (the plunger '76 having previously been depressed by the tool 112 to permit this position of the parts to be attained), the two hook portions $6 of the cap are in register with the two voids or notches 120' which are formed in the radial rim flange 88 (see FIGS. 3 and 7), and at this time have been brought from the positions shown in FIG. 5 to the positions shown in FIG. 8. Similar voids or notches 122 in the forwardly extending axial rim flange 16 of the lock barrel 14 (see FIG. 8) at the uppermost and lowermost regions of the rim flange establish points of entry and removal for the two hook portions 86 when the cap is applied to and removed from the lock assembly. The opposite sides of the two hook portions 36 at all times oppose and bear against the sides of the notches 122 so that at no time is the cap rotatable when it is in assembled relation with the barrel, the sides of the notches 122 and the sides of the hook portions 86 thus constituting circumferentially opposed shoulders which prevent rotation of the cap 80. Thus, when the lock shaft 42 has been turned throughout the additional 25 angular movement previously mentioned, the notches 12% are in register with the notches 122 and, consequently, with the hook portions 86 of the cap 8% so that the cap may be removed forwardly from the lock assembly by the simple expedient of pulling the key forwardly.

With the cap 8d thus removed from the lock assembly 10, the forward rotative shaft pins 66 of the split tumbler arrangements are exposed for removal, replacement or interchange as desired. Change-over operations may, of course, be accomplished by removal of one or more of the shaft pins 66 and substitution of replacement pins of different length. Such a procedure, however, entails considerable work on the part of the service personnel of vending machines who would be obliged to carry with them an assortment of tumbler pins, jigs for holding them in a classified manner, and tools for their manipulation. Additionally, a certain amount of bookkeeping would be required to correlate these replacement tumbler pins with the required keys to fit the locks after change-over operations had been instituted. A simpler procedure is to effect shaft pin interchange among the pins 66 of an individual lock assembly, an interchange between any two tumbler pins of a given lock assembly being sufiicient for all practical purposes to obviate contemplated lock tampering or unauthorized key retention on the part of a former Serviceman employee. Accordingly, in the following description of an exemplary change-over operation, it will be assumed that the two of the rotating shaft tumbler -pins 66 (labelled 66a and 66b respectively) are of unequal length and that the interchange operation is effected by switching the positions of these two tumbler pins as indicated by the double-headed arrow in FIG. 7.

If the shaft pins 66 are formed of steel or other magnetic material, a magnetic tool, such as the tool 130 of FIG. 7, may be employed to lift the pins 66a and 66b from their respective bores 68 and to reposition them, each in the bore formerly occupied by the other pin. If the pins are of a non-magnetic material, such as brass, then a pair of tweezers will sufice for the operation.

Upon arrival of the serviceman at the scene of any contemplated lock change-over operation, the man will first insert his original key in the lock assembly 10 in the usual manner and as previously described, whereupon the tumbler pin arrangements 64, 66 (see FIG. 4) will be shifted axially rearwardly to bring the splits into register with the plane of division between the fixed barrel 14 and the enlarged head 70 of the rotatable shaft 42, thus freeing the shaft for rotation with respect to the barrel 14. The key and shaft may then be turned in unison until such time as the plunger 76 engages the shoulder 108 (see FIG. 9) and the shaft 42 has turned through an angle of to withdraw the locking cam 5t) from behind the locking shoulder 54. The door panel 26 may then be swung to an open or partially open position where the notch 114 is accessible for insertion there-into of the tool 112. By pushing the tool 112 endwise through the opening 110, the plunger 76 is depressed so that it clears the shoulder 168. Further turning of the key 12 through an angle of approximately 25 will cause additional rotation of the shaft 42 until such time as the plunger 76 engages the shoulder 114 (see FIG. 10). At this time, the radial rim flange 88 of the shaft 42 will have been slid, so to speak, from its locking position behind the hook portions 86 of the cap 80 and these latter hook portions will be free to move axially forward through the voids or notches 122 (see FIG. 8) when pulling force is applied to or exerted upon the key 12. The lug 94, acting upon the inturned rim S1 of the cap 80, pulls the entire cap away from the barrel 14 as shown in FIG. 7, thus exposing the rotative shaft pins.

In order to prevent inadvertent turning movement of the shaft 42 away from its overrun 25 angular position and possible tumbler pin alignment with a con sequent forcible ejection of both shaft and barrel pins from the barrel 14 by the force of the springs 72 during changeover operations, a locking detent plunger 146) (see FIGS 4, 8a and 9b) is disposed within the previously mentioned sixth socket 62 and is urged or pressed forwardly by way of a spiral compression spring 142. A reduced forward extension 144 (see FIG. But) on the detent plunger 14f) affords a forwardly facing annular shoulder 146. Normally, the end of the extension 144 bears against the forward end face of the cap 811, as shown in FIG. 812, when the cap is in position within the protective washer 30, but when the cap is removed during change-over operations as previously described, the reduced extension 144 of the plunger 140 is projected into one of the notches 121] in the rim flange 88 while the main body portion of the plunger 14% is projected into a detent recess 14? (see FIGS. 4, 5 and 8b) in the rear face of the enlarged head 70 on the shaft 42. The plunger and recess thus lock the lock shaft 42 against return movement away from its overrun position and fixedly hold the shaft stationary during shaft pin manipulations.

With the rotative shaft pins 66 exposed and with the lock shaft 42 thus held against turning movement, shaft pin interchange as between the pins 66a and 66b may now be effected with no danger of shaft pin loss. The Serviceman, holding the key 12 and the cap 80 in one hand, may then employ the other hand to manipulate the tool and effect interchange of the two shaft pins 66a and 66b. After the interchange has thus been effected, the key 12 obviously will no longer fit the lock assembly 10. Such key may then be withdrawn from the loose cap 80 by effecting alignment or register of the lug 96 and the slot 94 and the new or replacement key 12A passed through the rim opening 92 so as to assemble said key loosely in the cap 80.

Thereafter, disregarding the angular position of the cap 80, the key 12A may be applied to the post 71 and turned until pin and key register takes place. While main taining this position of key and pin register, the cap 80 may be rotated to bring the two hook portions $56 into axial register with the voids 120 and 122, taking care that the notch 94 is at the top of the cap, after WhlCl'l the cap 80 may be pushed forwardly and into the protective washer 30.

To restore the lock to operation by the new key 12A, it is then necessary merely to rotate the key in a counterclockwise direction and thus turn the shaft 42 so that the plunger 76 leaves the shoulder 114 and rides past the shoulder 108 and into the normal 90 path of movement allotted to it by the two shoulders 1G6 and 108 which defines the relief area 104. Such return movement of the shaft from its overrun position is made possible by reason of the fact that replacement of the cap 8% in the protective washer 30 causes depression of the detent plunger 140, the end face of the cap 80 serving to press the plunger extension 144 rearwardly so that the plunger body is withdrawn from the detent recess. The return movement of the shaft 42 brings the rim flange 88 in front of the hook portions 86 of the cap 30 and thus locks the cap in position so that it cannot be removed.

At this point, the lock assembly has been restored to normal operation, utilizing the new key 12A. However, the key 12A cannot be removed from the lockassembly until the lug 96A thereon is brought into register with the notch 94 in the rim of the retaining rim 81 of the cap 80.

The invention is not to be limited to the exact arrangement of parts shown in the accompanying drawings or described in this specification as various changes in the details of construction may be resorted to without departing from the spirit or scope of the invention. For example, whereas the shoulder 114 has been described as being so disposed that it will permit the lock shaft 4 2 to overrun its locked position by an angle of approximately 25, a different location of this shoulder which Will permit a greater or lesser angular overrun of the lock shaft is contemplated, the particular degree of overrun not being critical. Similarly, although the interlock between the key-retaining cap St? and the lock shaft 42 comprises male hook portions 86 on the cap and female notches 120 on the shaft, a reversal of such male and female interlocking means may be resorted to. Therefore, only insofar as the invention has particularly been pointed out in the accompanying claims is the same to be limited.

Having thus described the invention what I claim as new and desire to secure by Letters Patent is:

1. In an axial pin-tumbler lock assembly, in combination, an open-ended tubular barrel presenting an internal axial bore and having an annular front end face and a forwardly extending axial rim flange encircling said front end face and, in combination therewith, defining a shallow forwardly opening recess, a lock shaft rotatable within said bore and having an enlarged circular head seated within and substantially filling said recess, an axial split tumbler arrangement including cooperating barrel and shaft pins axially slidable in the barrel and shaft head respectively, said shaft pins projecting forwardly of the head for cooperation -with a key and being freely removable endwise from the shaft head for purposes of pin interchange, an interrupted circular radial .rim flange on said shaft head, spaced forwardly of said annular end face, and defining in combination with the latter an annular channel behind the radial rim flange, said axial and radial rim flanges each being formed with a notch therein, the notch in said radial rim flange being movable into and out of registry with the notch in said axial flange upon turning movement of said lock shaft, a removable annular cap positioned forwardly of the axial rim flange and having a rearwardly extending hook portion which lies behind and normally interlocks with said radial rim flange to prevent forward removal of the cap, said shaft being rotatable Within the barrel between a first position wherein the tumbler arrangement is effective to maintain the lock assembly locked, and second and third positions wherein the tumbler arrangement is effective to maintain the lock assembly unlocked, said notches in the axial and radial rim. flanges, respectively, assuming positions of nonregistry when the shaft is in its first and second positions, and assuming a position of registry with each.

other when the shaft is in its third position, said notches, when in registry with each other, establishing a clearance void through the axial and radial rim flanges for forward passage of said hook portion of the cap and consequent removal of the cap from the lock assembly to expose said shaft head pins for interchange or replacement.

2. An axial pin-tumbler lock assembly as set forth in claim 1 and including, additionally, detent means for maintaining said shaft in its third position.

3. An axial pin-tumbler lock assembly as set forth in claim 1 and including, additionally, releasable detent means effective between the cap and barrel for maintaining said shaft in its third position.

4. An axial pin-tumbler lock assembly as set forth in claim 1 and including, additionally, releasable detent means effective between the cap and barrel for maintaining said shaft in its third position, and means automatically operable when said cap is in position forwardly of said axial rim flange for rendering said detent means ineffective.

5. An axial pin-tumbler lock assembly as set forth in claim 1 and including, additionally, a depressible locking detent plunger carried by said barrel, said shaft head being formed with a cooperating detent recess designed for registry with the plunger when the shaft is in its third position, said plunger being formed with an extension thereon engageable by said cap when the latter is in position in the lock assembly for maintaining the plunger depressed, said plunger being movable into said detent recess when the cap is removed from the lock assembly to lock the shaft in its third position.

6. An axial pin-tumbler lock assembly as set forth in claim 5 and wherein said depressible detent plunger is axially slidable in the barrel and wherein said extension on the plunger is engageable with a rearwardly facing surface on the cap.

'7. An axial pin-tumbler lock assembly as set forth in claim 6 and wherein said plunger is in axial alignment and register With the notch in said axial rim flange and is engageable with the hook portion of said cap.

8. In an axial pin-tumbler lock assembly, an openended tubular barrel presenting an internal axial bore and having an annular front end face and a forwardly extending axial rim flange encircling said front end face and, in combination therewith, defining a shallow forwardly opening recess, a lock shaft rotatable within said bore and having an enlarged circular head seated within and substantially filling said recess, an axial split tumbler arrangement including cooperating barrel and shaft pins axially slidable in the barrel and shaft head respectively, said shaft pins projecting forwardly of the head for cooperation with a key and being freely removable endwise from the shaft head for purposes of pin interchange, an interrupted circular radial rim flange on said shaft head, spaced forwardly of said annular end face, and defining in combination with the latter an annular channel behind the radial rim flange, said axial and radial rim flanges each being formed with a notch therein, the notch in said radial rim flange being movable into and out of registry with the notch in said axial flange upon turning movement of said lock shaft, a removable annular cap positioned forwardly of the axial rim flange and having a rearwardly extending hook portion which lies behind and normally interlocks with said radial rim flange to prevent forward removal of the cap, said shaft being rotatable within the barrel between a first position wherein the tumbler arrangement is effective to maintain the lock assembly locked, and second and third positions wherein the tumbler arrangement is effective to maintain the lock assembly unlocked, said notches assuming positions of non-registry when the shaft is in its first and second positions, and assuming a position of registry with each other when the shaft is in its third position, said notches in the axial and radial rim flanges respectively assuming positions of non-registry when the shaft is in its first and second positions, and assuming positions of registry when the shaft is in its third position, said notches, when in registry with each other, establishing a clearance void through the axial and radial rim flanges for forward passage of said hook portion of the cap and consequent removal of the cap from the lock assembly to expose said shaft head pins for interchange or replacement, and manually operable releasable latch means effective between the barrel and shaft and normally limiting the movement of the shaft to a range of movement between its first and second positions.

9. An axial pin-tumbler lock assembly as set forth in claim 8 and including, additionally, releasable detent means effective between the cap and barrel for maintaining said shaft in its third position, and means automatically operable when said cap is in position forwardly of said axial rim flange for rendering said detent means ineffective.

10. An axial pin-tumbler lock assembly as set forth in claim 8 and including, additionally, a depressible locking detent plunger carried by said barrel, said shaft head being formed with a cooperating detent recess designed for registry with the plunger when the shaft is in its third position, said plunger being formed with an extension thereon engageable by said cap when the latter is in position in the lock assembly for maintaining the plunger depressed, said plunger being movable into the recess when the cap is removed from the lock assembly to lock the shaft in its third position.

11. In an axial pin-tumbler lock assembly, an openended tubular barrel presenting an internal axial bore and having an annular front end face and a forwardly extending axial rim flange encircling said front end face and, in combination therewith, defining a shallow forwardly opening recess, a lock shaft rotatable within said bore and having an enlarged circular head seated within and substantially filling said recess, an axial split tumbler arrangement including cooperating barrel and shaft pins axially slidable in the barrel and shaft head respectively, said shaft pins projecting forwardly of the head for cooperation with a key and being freely removable endwise from the shaft head for purposes of pin interchange, an interrupted circular radial rim flange on said shaft head, spaced forwardly of said annular end face, and defining in combination with the latter an annular channel behind the radial rim flange, said axial and radial rim flanges each being formed with a notch therein, the notch in said radial rim flange being movable into and out of registry with the notch in said axial flange upon turning movement of said lock shaft, a removable annular cap positioned forwardly of the axial rim flange and having a rearwardly extending hook portion which lies behind and normally interlocks with said radial rim flange to prevent forward removal of the cap, said shaft being rotatable within the barrel between a first position wherein the tumbler arrangement is effective to maintain the lock assembly locked and second and third positions wherein the tumbler arrangement is effective to maintain the lock assembly unlocked, said notches in the axial and radial flanges respectively assuming positions of non-registry when the shaft is in its first and second positions, and assuming positions of registry with each other when the shaft is in its third position, said notches, when in register with each other, establishing a clearance void through the axial and radial rim flanges for forward passage of said hook portion of the cap and consequent removal of the cap from the lock assembly to expose the shaft head pins for interchange or replacement, combined limit stop and latch means effective between the barrel and shaft and normally limiting the movement of the shaft to a range of angular movement between, its first and second positions, said limit stop and latch means being manually releasable to allow the shaft to move from its second position to its third position.

12. An axial pin-tumbler lock assembly as set forth in claim 11 and including, additionally, a detent means for maintaining said shaft in its third position.

13. An axial pin-tumbler lock assembly as set forth in claim 11 and including, additionally, releasable detent means effective between the cap and barrel for maintaining said shaft in its third position.

14. An axial pin-tumbler lock assembly as set forth in claim 11 including, additionally, a depressible locking detent plunger carried by said barrel, said shaft head being formed with a cooperating detent recess designed for registry with the plunger when the shaft is in its third position, said plunger being formed with an extenson thereon engageable by said cap when the latter is in position in the lock assembly for maintaining the plunger depressed, said plunger being movable intosaid detent recess when the cap is removed from the lock assembly to lock the shaft in its third position.

15. In an axial pin-tumbler lock assembly, an openended tubular barrel presenting an internal axial bore and having an annular front end face and a forwardly extending axial rim flange encircling said front end face and, in combination therewith, defining a shallow forwardly opening recess, a lock shaft rotatable within said bore and having an enlarged circular head seated Withinand substantially filling said recess, an axial split tumbler arrangement including cooperating barrel and shaft pins axially slidable in the barrel and shaft head respectively, said shaft pins projecting forwardly of the head for cooperation with a key and being freely removable endwise from the shaft head for purposes of pin interchange, an interrupted circular radial rim flange on said shaft head, spaced forwardly of said annular end face, and defining in combination with the latter an annular channel behind the radial rim flange, said axial and radial rim flanges each being formed with a notch therein, the notch in said radial rim flange being movable into and out of registry with the notch in said axial flange upon turning movement of said lock shaft, a removable annular cap positioned forwardly of the axial rim flange and having a rearwardly extending hook portion which lies behind and normally interlocks with said radial rim flange to prevent forward removal of the cap, said shaft being rotatable within the barrel between a first position wherein the tumbler arrangement is effective to maintain the lock assembly locked and second and third positions wherein the tumbler arrangement is effective to maintain the lock assembly unlocked, said notches in the axial and radial flanges respectively assuming positions of non-registry when the shaft is in its first andsecond positions, and assuming positions of registry with each other when the shaft is in its third position, said notches, when in register with each other, establishing a clearance void through the axial and radial rim flanges for forward passage of said hook portion of the cap and consequent removal of the cap from the lock assembly to expose the shaft head pins for interchange or replacement, a depressible combined limit stop and latching plunger carried by said shaft within the axial confines of said bore, first and second opposed shoulders formed internally of the bore at circumferentially spaced regions and selectively engageable by said limit stop and latching plunger to establish the first and second positions of the shaft, a third shoulder formed internally of the bore and engageable with said combined limit stop and latching plunger to establish the third position of the shaft, there being an access opening in the wall of said barrel in radial alignment with said plunger when the latter is in position against said second shoulder to permit depression of the plunger by a suitable tool and consequent withdrawal of the plunger from said second shoulder to permit said shaft to be moved to its third position.

16. An axial pin-tumbler lock assembly as set forth in claim 15 and including, additionally, releasable detent means effective between the cap and barrel for maintaining said shaft in its third position.

17. In an axial pin-tumbler lock assembly, in combination, an open-ended, non-rotatable tubular 'barrel having an internal axial bore and annular front and rear end faces, a lock shaft rotatable within said bore and having an enlarged head presenting a rear end face in rotative sliding contact with said front end face, an axial split tumbler arrangement including cooperating barrel and shaft pins projecting forwardly of the head for cooperation with a key and being freely removable endwise from the shaft head for purposes of pin interchange, a forwardly and axially removable annular cap positioned forwardly of the barrel and encircling said shaft head, circumferentially opposed shoulders on the cap and barrel respectively for preventing rotation of the cap, said shaft being rotatable from a first angular unlocked position, through a second angular locked position, to a third overrun terminal position, relatively slidable axially opposed shoulders on the cap and shaft head respectively normally preventing removal of the cap, said slidable shoulders permitting forward removal of the cap when the lock shaft is in its terminal position, releasable detent means effective between the cap and barrel for maintaining said shaft in its third position, and means automatically operable when said cap is in position forwardly of the barrel and in shaft head-encircling relationship for rendering said detent means inoperative.

18. In an axial pin-tumbler lock assembly, in combination, an open-ended non-rotatable tubular barrel having an internal axial bore and annular front and rear end faces, a lock shaft rotatable within said bore and having an enlarged head presenting a rear end face in rotative sliding contact with said front end face, an axial split tumbler arrangement including cooperating barrel and shaft pins projecting forwardly of the head for cooperation with a key and being freely removable endwise from the shaft head for purposes of pin interchange, a forwardly and axially removable annular cap positioned forwardly of the barrel and encircling said shaft head, circumferentially opposed shoulders on the cap and barrel respectively for preventing rotation of the cap, said shaft being rotatable from a first angular unlocked position, through a second angular locked position, to a third overrun terminal position, relatively slidable axially opposed shoulders on the cap and shaft head respectively normally preventing removal of the cap, said slidable shoulders permitting forward removal of the cap when the lock shaft is in its terminal position, and manually operable releasable latch means effective between the barrel and shaft and normally limiting the movement of the shaft to a range of movement between its first and second positions.

19.,An axial pin-tumbler lock assembly as set forth in claim 18 and including, additionally, a depressible locking detent plunger carried by said barrel, said shaft head being formed with a cooperating detent recess designed for registry with the plunger being formed with an extension thereon engageable by said cap when the latter is in position in the lock assembly for-maintaining the plunger depressed, said plunger being movable into the recess when the cap is removed from the lock assembly to lock the shaft in its third position.

20. In an axial pin-tumbler lock assembly, in combination, an open-ended non-rotatable tubular barrel having an internal axial bore and annular front and rear end faces, a lock shaft rotatable within said bore andhaving an enlarged head presenting a' rear end face in rotative sliding contact with said front end face, an axial split tumbler arrangement including cooperating barrel and shaft pins projecting forwardly of the head for cooperation with a key and being freely removable endwise from the shaft head for purposes of pin interchange, a forwardly and axially removable annular cap positioned forwardly of the barrel and encircling said shaft head, circumferentially opposed shoulders on the cap and barrel respectively for preventing rotation of the cap, said shaft being rotatable from a first angular unlocked position, through a second angular locked position, to a third overrun terminal position, relatively slidable axially opposed shoulders on the cap and shaft head respectively normally preventing removal of the cap, said slidable shoulders permitting forward removal of the cap when the lock shaft is in its terminal position a depressible combined limit stop and latching plunger carried by said shaft within the axial confines of said bore, first and second opposed shoulders formed internally of the bore at circumferentially spaced regions and selectively engageable by said limit stop and latching plunger to establish the first and second positions of the shaft, and a third shoulder formed internally of the bore and engageable with said combined limit stop and latching plunger to establish the third position of the shaft, there being an access opening in the wall of said barrel in radial alignment with said plunger when the latter is in position against said second shoulder to permit depression of the plunger by a suitable tool and consequent withdrawal of the plunger from said second shoulder to permit the shaft to be moved to its third position.

References Cited by the Examiner UNITED STATES PATENTS 3,102,412 9/1963 Christopher -363 EDWARD C. ALLEN, Primary Examiner.

ALBERT H. KAMPE, Examiner. B. R. GAY, Assistant Examiner. 

1. IN AN AXIAL PIN-TUMBLER LOCK ASSEMBLY, IN COMBINATION, AN OPEN-ENDED TUBULAR BARREL PRESENTING AN INTERNAL AXIAL BORE AND HAVING AN ANNULAR FRONT END FACE AND A FORWARDLY EXTENDING AXIAL RIM FLANGE ENCIRCLING SAID FRONT END FACE AND, IN COMBINATION THEREWITH, DEFINING A SHALLOW FORWARDLY OPENING RECESS, A LOCK SHAFT ROTATABLE WITHIN SAID BORE AND HAVING AN ENLARGED CIRCULAR HEAD SEATED WITHIN AND SUBSTANTIALLY FILLING SAID RECESS, AN AXIAL SPLIT TUMBLER ARRANGEMENT INCLUDING COOPERATING BARREL AND SHAFT PINS AXIALLY SLIDABLE IN THE BARREL AND SHAFT HEAD RESPECTIVELY, SAID SHAFT PINS PROJECTING FORWARDLY OF THE HEAD FOR COOPERATION WITH A KEY AND BEING FREELY REMOVABLE ENDWISE FROM THE SHAFT HEAD FOR PURPOSES OF PIN INTERCHANGE, AN INTERRUPTED CIRCULAR RADIAL RIM FLANGE ON SAID SHAFT HEAD, SPACED FORWARDLY OF SAID ANNULAR END FACE, AND DEFINING IN COMBINATION WITH THE LATTER AN ANNULAR CHANNEL BEHIND THE RADIAL RIM FLANGE, SAID AXIAL AND RADIAL RIM FLANGES EACH BEING FORMED WITH A NOTCH THEREIN, THE NOTCH IN SAID RADIAL RIM FLANGE BEING MOVABLE INTO AND OUT OF REGISTRY WITH THE NOTCH IN SAID AXIAL FLANGE UPON TURNING MOVEMENT OF SAID LOCK SHAFT, A REMOVABLE ANNULAR CAP POSITIONED FORWARDLY OF THE AXIAL RIM FLANGE AND HAVING A REARWARDLY EXTENDING HOOK PORTION WHICH LIES BEHIND AND NORMALLY INTERLOCKS WITH SAID RADIAL RIM FLAMGE TO PREVENT FORWARD REMOVAL OF THE CAP, SAID SHAFT BEING ROTATABLE WITHIN THE BARREL BETWEEN A FIRST POSITION WHEREIN THE TUMBLER ARRANGEMENT IS EFFECTIVE TO MAINTAIN THE LOCK ASSEMBLY LOCKED, AND SECOND AND THIRD POSITIONS WHEREIN THE TUMBLER ARRANGEMENT IS EFFECTIVE TO MAINTAIN THE LOCK ASSEMBLY UNLOCKED, SAID NOTCHES IN THE AXIAL AND RADIAL RIM FLANGES, RESPECTIVELY, ASSUMING POSITIONS OF NONREGISTRY WHEN THE SHAFT IS IN ITS FIRST AND SECOND POSITIONS, AND ASSUMING A POSITION OF REGISTRY WIH EACH OTHER WHEN THE SHAFT IS IN ITS THIRD POSIITON, SAID NOTCHES, WHEN IN REGISTRY WITH EACH OTHER, ESTABLISHING A CLEARANCE VOID THROUGH THE AXIAL AND RADIAL RIM FLANGES FOR FORWARD PASSAGE OF SAID HOOK PORTION OF THE CAP AND CONSEQUENT REMOVABL OF THE CAP FROM THE LOCK ASSEMBLY TO EXPOSE SAID SHAFT HEAD PINS FOR INTERCHANGE OF REPLACEMENT. 